package com.example.demo.controller;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

@Controller
@ComponentScan
public class GetLoginCodeController {


    @RequestMapping("/getCode")
    @ResponseBody
    public void getCode(HttpServletRequest request, HttpServletResponse response) throws IOException {

        // 使用java图形界面技术绘制一张图片
        int charNum = 4;
        int width = 20 * 4;
        int height = 28;
        // 1. 创建一张内存图片
        BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        // 2.获得绘图对象
        Graphics graphics = bufferedImage.getGraphics();
        // 3、绘制背景颜色
        graphics.setColor(Color.cyan);
        graphics.fillRect(0, 0, width, height);
        // 4、绘制图片边框
        graphics.setColor(Color.GRAY);
        graphics.drawRect(0, 0, width - 1, height - 1);
        // 5、输出验证码内容
        graphics.setColor(Color.RED);
        graphics.setFont(new Font("宋体", Font.BOLD, 22));
        // 随机输出4个字符
        String s = "ABCDEFGHGKLMNPQRSTUVWXYZ23456789";
        Random random = new Random();
        // session中要用到
        String msg = "";

        int x = 5;
        for (int i = 0; i < charNum; i++) {
            int index = random.nextInt(32);
            String content = String.valueOf(s.charAt(index));
            msg += content;
            graphics.setColor(new Color(random.nextInt(128), random.nextInt(128), random.nextInt(128)));
            graphics.drawString(content, x, 22);
            x += 20;
        }

        request.getSession().setAttribute("codeSession", msg);
        System.out.println("codeSession = " + msg);
        // 6、绘制干扰线
        graphics.setColor(Color.GRAY);
        for (int i = 0; i < 5; i++) {
            int x1 = random.nextInt(width);
            int x2 = random.nextInt(width);
            int y1 = random.nextInt(height);
            int y2 = random.nextInt(height);
            graphics.drawLine(x1, y1, x2, y2);
        }
        // 释放资源
        graphics.dispose();
        // 图片输出 ImageIO
        ImageIO.write(bufferedImage, "jpg", response.getOutputStream());
    }
}
